This application is a substitute application for U.S. patent application Ser. No. 249,083, filed Mar. 30, 1981, which was abandoned before the filing of this application. The device of this application was first described in Disclosure Document No. 067347 filed Jan. 9, 1978 and was described a second time in Disclosure Document No. 068473 filed Feb. 13, 1978.
(1) Field of the Invention
This invention pertains to heat exchangers generally and specifically to a heat retrieving device in which a rotatable fresh air intake pipe is positioned within a hot flue gas exhaust pipe to heat the incoming fresh air to be directed downward through the interior pipe. Air scoops are used on bearing-mounted pipe sections to direct the weathervane and fresh air intake into the wind.
(2) Description of the Prior Art
The use of a pipe within a flue pipe for heating or preheating air to retrieve some of the heat usually escaping through the flue pipe of a stove or furnace is well known in the prior art. Many devices, both simple and complex, have been devised for this purpose. Some are simple recirculation devices and fail to provide additional fresh air. The provision of additional fresh air is a desirable feature to replenish the supply of oxygen within the heated structure. Also, the introduction of fresh, preheated air containing oxygen will improve the combustion in the furnace or fireplace. The device of the present invention is designed to overcome many deficiencies found in the prior art.
U.S. Pat. No. 2,479,413 discloses a flue heat exchanger having a complex pipe within a pipe structure and utilizes a fan for circulation. U.S. Pat. No. 2,916,983 discloses a pipe within a pipe system having a fresh air intake solely for the purpose of cooling hot flue gasses in the flue pipe. U.S. Pat. No. 3,691,930 teaches a wind control flue and air intake assembly to balance the effects of changes in wind velocity and direction for the fresh air intake of a gas furnace installation. No heat exchanger is involved.
U.S. Pat. No. 3,913,663 discloses a circuitous chamber installed within a flue pipe to preheat incoming fresh air. U.S. Pat. No. 4,034,803 teaches another type of heat exchanger for preheating air by flue gasses. U.S. Pat. No. 4,040,477 teaches still another heat exchanger which is complex in structure and which uses flue gasses to heat incoming fresh air for discharge into a room. Blowers are utilized to force the air and hot gasses through the system. U.S. Pat. No. 4,050,628 discloses another type of heat exchanger whereby flue gasses are used to warm incoming fresh air.
All the prior art devices, whether patented or not, are of a complex variety and many require fans to force either fresh air or hot gasses through the heat exchanger unit. The principle objective of the present invention is to provide a fresh air, flue pipe heat exchanger, which will reclaim heat for a substantial length of said flue pipe, by running to its outside portion, without being in danger of sucking in gasses from its exhaust exit.
Because smoke either rises vertically or is blown in the opposite direction of the fresh air scoop, said exhaust exit will always face the opposite direction of the prevailing wind. Thus, the present invention will prevent down drafts.
Also, the present invention takes advantage of wind pressure to force cold air down the fresh air duct. Since the fresh hot air vent can easily be adapted to utilize the draft created by the furnace fan or blower, the present invention may not require any additional source of power to operate. However, this arrangement may prove unfeasible in some heating systems, so a fan or blower device at the fresh hot air intake vent will be optional.